The gastrointestinal tract is part of the endocrine system, which is all about hormones, so we can assume that the gastro tract probably does release hormones. And our assumption is correct — it releases hormones such as gastrin (most importantly) and secretin, which help regulate the process of digestion.
Explanation: Many greenhouse gases occur naturally in the atmosphere, such as carbon dioxide, methane, water vapor, and nitrous oxide, while others are synthetic.
